1902 house next to a warehouse. Damp issues

[Charina5]

Hello, our end-of-terrace London house was built in 1902. On one side is a large warehouse that's used by builders to store their materials. On the other is my next door neighbour. We have damp problems downstairs on the warehouse side. We had damp in the front living room wall and we actually ended up removing all the plaster and taking it back to brick. The bricks were damp lower down the wall (from the front window and damp into the middle of the room. See photos). We ran an industrial dehumidifier for a few weeks. I wanted to re-plaster in lime to let the house breathe. My builder ended up injecting a damp-proof liquid into the bricks (internally), then he applied a waterproof slurry to half way up the wall and then replastered in sand and cement (he also checked the air brick vents, checked the gutters and drains. These were all fine). I said several times that I wanted lime plaster but he insisted that he had done slurry and sand and cement on a lot of London properties and never had a problem. I am fully aware that I should have used breathable materials, but my question is about the cold, damp warehouse next to my house. If tanking a period wall is a really bad idea, how should a damp wall be remedied if it is directly next to a cold, uninhabited, unheated warehouse?? I am aware that I need to try to contact the owner of the warehouse to get them to check the warehouse for water leaks etc, but if I can't get hold of the owner (or, in the interim) how am I meant to tackle internal damp with possible water ingress from the warehouse next door, or at any rate, the warehouse is never heated so that side of my house is always colder)? I think that a lot of advice on here about using breathable materials for a period property is either for a detached period property or a terraced house where there are next door neighbours either side. What's the advice for houses next to cold, uninhabited buildings? Please don't advise that I sell the house. My husband and I can't just yet. Thanks for your help.

 

[IHateDamp]

What were the symptoms of damp in your wall ? How long had you experienced them ?

Have you observed what happens on a stormy rainy day to that down pipe emptying on the builders side?

 

[alexander]

the roof tiles adjoining the building are not sealed should be stepped lead flashing down the wall, that looks like cemented tiles which will leak down the wall

 

[larry]

So firstly please bear in mind I am not a professional at all and will happily defer/stand aside for more experienced members... only somebody who's had damp in own property and spent far too long thinking about and undoing previous work...

It sounds to me like you haven't yet worked out why the wall is damp, but instead have proceeded with a potential solution that may not address the actual cause.

Understanding why it is damp is the first step which you want to be certain on before moving onto solutions. It's also a big reliever for anxiety, as you know what you are dealing with. The 'chuck a solution on it' approach doesn't help with anxiety as you've got no idea if it's the right solution or not. There's also a risk it might make it worse...

Your own logic, reasoning and research will be probably be the best way to approach this - many trades don't seem to understand these key issues. damp proof experts are generally sales people

So you've just got to start ruling in and ruling out potential solutions. I think the question is, is this just a cold wall, or a cold and wet wall? Where is it most wet?

If the water is coming down from the roof or that drainpipe and the wall is getting wet from water running down it on the outside (it looks like the remedial works by your builder have been done to the same corner as the drain?) then I don't see how the work you've had done is going to make any difference (unless perhaps water is pooling on the ground and then soaking back up the wall, but even so it's the wrong solution).

But if the roof is sealed and dry then where is the water coming from? Maybe something is going on on that drain area? Have you had a look at what happens when it rains? Does water collect anywhere? (And if so, the remedial works aren't the solution here, sorting out the - render touching the ground, water pooling next to the wall, too high groud levels etc - is the key)

The injections from the builder imply they thought water was coming up from the ground, but I don't see why it might not equally just be condensation.... cold wall, water in air condenses on the wall, and if old paints etc, water gets trapped behind plaster, can't dry get out as a vapour, so wall gets wet. Solution here is to replaster in lime and breathable paints - and the injections etc done by your builder will be no help at all

You've gotta find a way to look at the wall on the other side. Is it wet? Evidence of leaks etc? And is it painted at all or coated? It's a solid wall so whatever is going on the other side of the wall is relevant to how it can dry out. I can't believe that your builder proceeded with this without seeing the wall from the other side....

 

[Charina5]

What were the symptoms of damp in your wall ? How long had you experienced them ?

Have you observed what happens on a stormy rainy day to that down pipe emptying on the builders side?

Thanks for your questions. We had wallpaper bubbling off in the living room. When we finally plucked up the courage to peel it back, there were pink and black mold spores on the wallpaper and walls and it smelt awful. Because we thought it might be a plaster wall, we stripped the wallpaper from ceiling to floor (it came off very easily and smelt awful) we cleaned it the mold and mildew off with distilled white vinegar (a few times to be sure) and than we had the wall cut off back to brick (and ran an industrial dehumidifier for 3 weeks). There was also a picture hook at 5ft height on the window wall that had rusted and was actually wet to touch. The builder said that 'rising damp' can go up to 1.5m high. The internal wall was wet well into the living room towards the middle of the house (towards the back dining room) which makes us think that there's some damp in the warehouse.

No, we haven't yet observed what's going on with the downpipe on the builders side. But there was a gap of 3-5 cm in between the builder's warehouse and our house. That was sealed up with breathable render.

 

[Charina5]

the roof tiles adjoining the building are not sealed should be stepped lead flashing down the wall, that looks like cemented tiles which will leak down the wall

Fab, thanks so much. We had a roofer look at the top and he charged us £500 to make a few rubbish patch repairs. He did not say anything about the lack of stepped lead flashing. We were ripped off by him. He was the first trades person I called and he probably smelt our panic.

 

[Charina5]

So firstly please bear in mind I am not a professional at all and will happily defer/stand aside for more experienced members... only somebody who's had damp in own property and spent far too long thinking about and undoing previous work...

It sounds to me like you haven't yet worked out why the wall is damp, but instead have proceeded with a potential solution that may not address the actual cause.

Understanding why it is damp is the first step which you want to be certain on before moving onto solutions. It's also a big reliever for anxiety, as you know what you are dealing with. The 'chuck a solution on it' approach doesn't help with anxiety as you've got no idea if it's the right solution or not. There's also a risk it might make it worse...

Your own logic, reasoning and research will be probably be the best way to approach this - many trades don't seem to understand these key issues. damp proof experts are generally sales people

So you've just got to start ruling in and ruling out potential solutions. I think the question is, is this just a cold wall, or a cold and wet wall? Where is it most wet?

If the water is coming down from the roof or that drainpipe and the wall is getting wet from water running down it on the outside (it looks like the remedial works by your builder have been done to the same corner as the drain?) then I don't see how the work you've had done is going to make any difference (unless perhaps water is pooling on the ground and then soaking back up the wall, but even so it's the wrong solution).

But if the roof is sealed and dry then where is the water coming from? Maybe something is going on on that drain area? Have you had a look at what happens when it rains? Does water collect anywhere? (And if so, the remedial works aren't the solution here, sorting out the - render touching the ground, water pooling next to the wall, too high groud levels etc - is the key)

The injections from the builder imply they thought water was coming up from the ground, but I don't see why it might not equally just be condensation.... cold wall, water in air condenses on the wall, and if old paints etc, water gets trapped behind plaster, can't dry get out as a vapour, so wall gets wet. Solution here is to replaster in lime and breathable paints - and the injections etc done by your builder will be no help at all

You've gotta find a way to look at the wall on the other side. Is it wet? Evidence of leaks etc? And is it painted at all or coated? It's a solid wall so whatever is going on the other side of the wall is relevant to how it can dry out. I can't believe that your builder proceeded with this without seeing the wall from the other side....

Thanks so much for your help here. I appreciate it.

The builder took up some floor boards on the inside of the house next to the warehouse wall (I told him to) and he unblocked the air vent that was only partially blocked by a bit of concrete (this is on the warehouse side of the house) and he also showed me that the original Victorian slate damp proofing had crumbled. He said that water was breaching that and causing rising damp.

There is also damp in wall in the middle of the house (where the living room meets the dining room. It's a through lounge/dining room on the warehouse side). The reason I think that it's not purely condensation is because there are recently rusted nails in the floor boards (there are rust marks on the underside of the rug). We only saw this recently (we couldn't remove all the plaster on that side of the wall because we stupidly did the remedial works without clearing the whole room. I have MS and my husband has full blown osteoporosis and we are not strong enough to move furniture. We couldn't face it so we just cleared the front end of furniture and moved everything to the middle of the room and covered it all in dust sheets).

Because we have damp/mildew under the wall paper in the middle of the room (rather than just at the front of the house), and because the warehouse is uninhabited and unheated, it's making me think that moisture is coming in from the warehouse.

I think my initial query was, if I can never get to the bottom of any damp/moisture in the warehouse (say, if I can never get hold of the owner. The builders next door rent the space. What if the owner goes AWOL because they don't want to start dealing with issues from us?), then what options do I have if all the advice is that one is not supposed to tank (waterproof) the wall of a period home?

 

[larry]

there was a gap of 3-5 cm in between the builder's warehouse and our house.

Sorry, can you explain this? Are the buildings actually together? Do you mean there is a small gap between the buildings all the way along the wall, and the warehouse isn't directly built off your wall?

If so is this an air gap and were you able to look down it before rendering over it?

 

[larry]

) and he unblocked the air vent that was only partially blocked by a bit of concrete (this is on the warehouse side of the house) and he also showed me that the original Victorian slate damp proofing had crumbled. He said that water was breaching that and causing rising damp

Where was the air vent going to, I presume sub floor but good to be clear.

What was evidence of the crumbled DPC?

And was the plaster bridging the DPC or anything else doing so?

 

[larry]

damp/mildew under the wall paper in the middle of the room (

Is your plaster a lime base which has had a gypsum plaster skim on top at some stage, then wallpaper above, and then paint on top of that?
Do you know when it was painted?

 

[Cubist]

Just to be clear on my understanding from your first post;

• There is No indication of damp in or on the party walls of the upper floor?
• There are no damp patches high up and near the ceilings of either the first floor bedrooms or those on the ground floor?

Some additional questions;

• Are the damp patches on the ground floor nearer to the front of the property?
• How does the water captured into the down pipe from your roof exit?
  • Does it flow into an underground pipe or does it empty into an open/gridded drain?
• Is the road outside the property more or less level with the front door or is there a step or two down to the pavement?

 

[Charina5]

Sorry, can you explain this? Are the buildings actually together? Do you mean there is a small gap between the buildings all the way along the wall, and the warehouse isn't directly built off your wall?

If so is this an air gap and were you able to look down it before rendering over it?

Hello, sorry for late reply. If you look at the photo of the front of the house you will see a thin strip of concrete between the warehouse and the yellow wall of the house. That was the gap. It closed up where the old lead flashing meets the house and therefore it was not possible to look down it before it was filled. The builders used a breathable render to fill the gap. It was an air gap and we thought that meant that rain was able to get into that side of the house and soak the wall. I am not sure if there was also a gap further down the wall because there was an old wooden fence post embedded in the wall which held the side front garden fence (which we also thought might contribute to damp in the wall because the wooden post would get wet when it rained). The builder took the wooden post out. Filled the gap with render and installed a new wooden post on top the render to hold the side garden fence panel.

 

[Charina5]

Where was the air vent going to, I presume sub floor but good to be clear.

What was evidence of the crumbled DPC?

And was the plaster bridging the DPC or anything else doing so?

Hello again, the air vent go to the subfloor. I had the builder take up the floor boards in the living room at the front of the house below the window and the air vents were fairly clear with one which had a bit of concrete stuck behind which the builder chipped away and cleared. Both air vents are now fully cleared. The sub-floor was clear of debris/rubbish/soil when we took the floor boards up, so there wasn't an issue with damp rubbish/damp soil holding moisture which would contribute to 'rising damp'.

The evidence for the crumbled slate DPC was the builder holding a piece of slate to show me. He showed me where he picked it off (so I don't think he just grabbed a piece of slate that was lying around under a floor board and pretended that the Victorian DPC had crumbled. I wouldn't put that past some builders!)

I don't know if the plaster was bridging the DPC. I didn't know to ask that. There's so much to learn with old houses!

 

[Charina5]

Is your plaster a lime base which has had a gypsum plaster skim on top at some stage, then wallpaper above, and then paint on top of that?
Do you know when it was painted?

I tried to google lime plaster (what it looks like). The plaster under the wall paper is pink so I don't think it was a sand and cement mix. Whether it was gypsum, I am not sure. I did post some photos to Facebook to seek advice and a few people thought it was lime.

We bought the house 7 years ago and it was already painted. We don't know when.

 

[sgking]

A different consideration here but have you got a stop tap near to where the damp is? A leaking stop tap or service pipe from stop tap into your home could cause damp until it is fixed.

 

[larry]

OK, well here's a few more thoughts - and again, I doff my hat to others on here who are more knowledgeable

Cubist's questions are important clarifications also

But some initial instincts:
* If there's a air gap between your house and their warehouse, then what's going on inside the warehouse is less important than if your house is directly adjoining the warehouse (unless they've got some massive water issue that's letting water run into the ground or something)
* Given there's an air gap, I'd love to know now what the outer most coating of the wall is... do you know - bare brick etc? Would be handy if breathable
* If the roof has been letting water in before the repairs above then and running down the wall then as hinted at by cubist you'd expect the location of the damp accordingly i.e. higher up.
* It sounds like you have had a gypsym plaster skim (thin pink layer) on top of original lime plaster (probably whiter underneath) - have a look at the edges of the plaster where it meets the brick.
* But whatever the source of the water, the paint and wallpaper and plaster will have made it harder for the wall to dry out once it got wet.
* There is a considerably compelling view that 'rising damp' is poorly defined (but read up about capillary action of water in bricks...), but solutions are not about locking the moisture away but about letting the materials the opportunity to dry out naturally ('breathe') by using materials that do not block the passage of water.


PS Don't at all say 'stupidly' in your decision making. There is an enormous industry built up around selling unnecessary solutions and many tradespeople do not understand how water moves in a property (I am absolutely not claiming expertise myself either!). Calling somebody when you've got a problem who then offered you a solution is not a silly thing to do, even if it's had a possibly unfortunate outcome.